1. Field of the Invention
This invention relates to a curtain apparatus which includes one or more fixed woven mesh metal curtains and/or one or more moveable woven mesh metal curtains mounted within slots contained in a top plate of a hood structure, such as of an industrial furnace.
2. Description of Prior Art
Steel woven mesh curtains have been used to cover openings of descalers used in steel mills for the purpose of preventing scale, slag and other undesirable debris from discharging through an opening, a hood or other cover structure of the descaler. In a descaling operation, high-pressure sprays are used to remove scale from bars, rods, strips and the like being processed. In a descaling operation, moisture is introduced between work rolls and stock so that the moisture vaporizes instantaneously with explosive effects for removing scale. High-pressure sprays, which impinge on both the top and bottom surfaces of a slab, are applied at pressures of as much as 3000 psi. The continuous hot-strip mill method of removing scale has been adopted for plate-mill methods. Thus, due to the relatively great pressures and explosive effects, scale is discharged at a very high acceleration and velocity toward an opening of a descaler. Thus, it is apparent that there is a need for a curtain apparatus that can withstand the forces created by water, scale particles and other pieces flying at such high accelerations and velocities.
Conventional curtain assemblies use woven mesh curtains, chains or plates, all typically constructed of strong materials, such as a variety of stainless steels or high-carbon steel. It is known that woven mesh metal curtains are constructed of fabrics comprising alternating left-hand and right-hand spirals of metal nested together and joined by three or more straight connecting rods. Conventional curtain apparatuses use curtains which are fixedly attached to an inside surface of a descaler hood or other cover structure, and use other curtains which are secured to moveable guide arms of the descaler or other milling apparatus. However, such moving curtains are pinned, welded or bolted to such guide arms, thus requiring extensive labor and shutdown periods for installation and removal.
Other conventional curtain apparatuses include a moveable curtain installed within a slot of the hood. However, such moving curtains are also pinned, welded or bolted to a bracket on the moveable guide arm, thus requiring entry into the hood for repair or removal of the curtains.
It is apparent that conventional curtain apparatuses require shutdown of the milling operation in order to install, remove or maintain either moveable or fixed curtains. Thus, it is apparent that there is a need for a curtain apparatus which can be easily removed, maintained and installed from outside of the hood or other equivalent cover structure.